Preflight reports "document contains an embedded file entry" on every PDF during PDF/A conversion (no visible attachment)

Community Manager

@affectionate_society4946 I hope you are doing well.

The product team is still working on isolating the issue, and we will update here once the fix is available.

Thanks for your cooperation on this.

Regards,

Anand Sri.

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T

TCH MD

Participant

Any updates on this? It’s been almost a month and it’s a serieus problem which effects my work for my clients. This issue means I am no longer in compliance with the agreements I have with my clients.

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Bettina Knell

Participant

Same issue here on macOS 26.6.2 with Acrobat Pro 26.002.21931 and InDesign 21.5. Every PDF fails, including a fresh one-line test file.

I looked into the file structure, and I believe I found the cause: Acrobat itself embeds a C2PA Content Credentials manifest during the PDF/A conversion.

- Before conversion, the PDF contains no embedded files at all.

- After running "Convert to PDF/A-2b", the catalog has an /AF array with file specifications named like "Acro00000B7D", with /AFRelationship /C2PA_Manifest.

- The embedded stream is a C2PA manifest (JUMBF), signed by "Adobe Acrobat 26.2.21931", but labelled as application/pdf.

- This is the "embedded file which is not a PDF" that Preflight complains about. The conversion then falls back to "Convert page content to image", so the text gets rasterized and the file is still not compliant.

So the problem does not come from the source PDFs, third-party plug-ins or job options. It is Acrobat's own Content Credentials feature conflicting with PDF/A-1/2/4, which do not allow this kind of embedded file.

Hopefully this helps the product team narrow it down. A setting to disable Content Credentials for PDF/A output would already solve it.

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Community Manager

Thanks for the details @Bettina Knell

This is helpful, and I will share it with the product team as additional information for the investigation.

Regards,

Anand Sri.

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affectionate_society4946

Participant

s there any resolution to this? Could we get an installer for 21901? This was the last stable version we had. Thanks!

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Meenakshi Negi

Community Manager

Hi affectionate_society4946,

Thank you for reaching out, and sorry for the trouble caused.

This issue has already been reported to the team. You can refer to the following page for the installer of 26.002.21901: https://www.adobe.com/devnet-docs/acrobatetk/tools/ReleaseNotesDC/index.html.

Thanks,

Meenakshi

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Mark25045282vuw1

Participating Frequently

I'm experiencing the same issue. InDesign files that we've previously exported to PDF and converted to PDF/A are now showing this error when using the Pre-flight tool.

We are using InDesign 21.5.1 and Acrobat 2026.002.21931.

The PDFs do not contain any visible attachments, and files that have successfully converted to PDF/A in the past are now reporting:

"PDF contains EF (embedded file) entry."

As a workaround, we were able to successfully convert the same PDFs to PDF/A using Acrobat's Save As PDF/A function. This suggests the PDFs themselves may not contain genuine embedded files, and that the issue may be related to the current Preflight validation/conversion process.

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Community Manager

Thanks for sharing the details @Mark25045282vuw1

Sorry for the trouble. We have raised this with the product team and have shared the above information.

We’ll update the thread as soon as the issue is resolved. Thanks for your cooperation on this.

Regards,

Anand Sri.

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M

Mark25045282vuw1

Participating Frequently

Thanks, just as some follow up - I’ve tried saving an optimised PDF, with remove attachments checked. Also, the pre-flight panel tools to discard attachments. I even tried creating a new simple A4 blank document and that failed the check.

As a further check, I took a PDF-A file we saved last year, clicked the ‘enable editing’ button in the blue PDF-A notice, and it failed with the same error.

If there a way to step back a version to last year’s version? This is possible to do with InDesign or Photoshop, in the Adobe CC app.

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Participating Frequently

I have had these plug-ins forever and I can’t do my job without them. The PDF/A checkmark is locked so I can’t stop the embedded file discovery or change it. IT has to do it. This started to happen when Microsoft made an update to my computer. This is not the first time they have done so and something weird starting happening with my Adobe. Thanks for your help anyway.

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Community Manager

Hello @Colorful_uniqueness3376

We have reported this issue to the product team as a bug for further investigation. The team is working to isolate the issue and develop a fix. We’ll update here once the fix is available.

Thanks for your cooperation on this.

Regards,

Anand Sri.

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D

DFWTechGuy

Participating Frequently

If this is happening with every PDF, even newly created/simple PDFs, I wouldn't assume the files all have hidden attachments.

First check Preflight > Options > Browse Internal PDF Structure and look for an actual embedded file entry. Adobe provides this specifically for investigating Preflight mismatches.

There also appears to be a recent Adobe Community report with the same "embedded file entry" error happening across every document, so this may be related to the current Acrobat/Preflight version rather than the PDFs themselves.

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Participating Frequently

I have always had Toolbox, I need this so I don’t think that one is the one doing it. The other is new…..

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Community Manager

@Colorful_uniqueness3376 Can you please share more about this?

Regards,

Anand Sri.

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Participating Frequently

Thank you, we will try that.

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Participating Frequently

The results panel shows no embedded file.

This is what I have Adobe Pro for Pharma / Windows the error appears when I run either one.

Version: 26.2.21931.0
Creation Date: 2026/09/15
Creation Time: 9:09:44 PM
c:\program files (x86)\adobe\acrobat dc\acrobat\plug_ins\autobookmark\autobookmark.api
Version: 8.8.5.0
Creation Date: 2026/07/01
Creation Time: 9:58:24 AM
c:\program files (x86)\adobe\acrobat dc\acrobat\plug_ins\csc\toolbox.api
Version: 6.4.1.0
Creation Date: 2022/08/31
Creation Time: 5:11:50 PM
C:\Program Files (x86)\Adobe\Acrobat DC\Acrobat\plug_ins\IA32.api
Version: 26.2.21931.0
Creation Date: 2026/09/15
Creation Time: 9:09:44 PM
C:\Program Files (x86)\Adobe\Acrobat DC\Acrobat\plug_ins\Updater.api
Version: 26.2.21901.0
Creation Date: 2026/09/10
Creation Time: 1:31:08 PM

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https://helpx.adobe.com/acrobat/using/analyzing-documents-preflight-tool-acrobat.html

Community Manager

@Colorful_uniqueness3376 Thanks for the details.

Test with the third-party plugins disabled (do this first). You have AutoBookmark (Evermap, autobookmark.api) and a CSC/toolbox.api plugin loaded. Plugins like these can add data/attachments or interact with the file in ways that leave an /EF entry, and it is quick to rule out:

Preferences (Ctrl+K) > General > Application Startup > tick "Use only certified plug-ins", then restart Acrobat and re-run the PDF/A Preflight.
Or, more thoroughly, rename the plugin folders so they do not load: C:\Program Files (x86)\Adobe\Acrobat DC\Acrobat\plug_ins\autobookmark and \csc (rename to autobookmark_off, etc.), then restart and retest.
If the "embedded file entry" error stops with plugins disabled, one of them is the cause (or is adding the /EF entry when the PDF is produced/processed).

Check the source workflow for an embedded .joboptions. If your PDFs are produced via Distiller or the Adobe PDF printer with "Save Adobe PDF Settings Inside PDF File" enabled, that embeds a hidden .joboptions file, an /EF entry, in every PDF, which never shows as a normal attachment but fails the PDF/A check. Turn it off in Distiller > Settings > Edit Adobe PDF Settings > Advanced, and re-create a test PDF.

Check your validated pharma Preflight profile. "Adobe Pro for Pharma" deployments usually run a customised/locked PDF/A profile for regulatory submissions. If the profile's "standards compliance for embedded files" options are misconfigured, it can flag every file. Since a validated config is often locked, this is worth checking with your internal Acrobat/validation admin rather than changing it yourself, especially in a GxP environment.
Strip it regardless: run a Preflight fixup to remove embedded files/attachments (it removes structural /EF entries even when nothing is visible), then re-run the PDF/A check.
If the embedded content is legitimate and required, target PDF/A-2 or PDF/A-3 instead of PDF/A-1, both allow embedded files (PDF/A-3 allows any file type), so the check will pass.
Because this is a validated/regulated deployment, disabling plugins, changing Distiller settings, or editing a locked Preflight profile may need to go through your internal Acrobat admin/validation team, and any change should be documented per your change-control. That is also the group that can tell you whether the profile or a plugin is the common factor across every PDF.

Reference help articles: http://helpx.adobe.com/acrobat/desktop/protect-documents/redact-pdfs/redact.html

https://helpx.adobe.com/acrobat/using/pdf-x-pdf-a-pdf.html

Regards,

Anand Sri.

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